JP2001028149A - Optical recording medium and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an optical recording medium and its manufacturing method, which prevent or suppress a lubricant from sticking or transferring to a light exit surface of a solid immersion lens. SOLUTION: This optical recording medium 10 comprises a reflecting layer 2, a recording layer 4, a protective layer 6 and a lubricating layer 7 on a substrate 1 in this order. By heating the lubricating layer 7 or/and irradiating the lubricating layer 7 with UV the lubricant bonding ratio is increased up to 60% or above and the quantity of a physically adsorptive lubricant contained in the lubricating layer 7 is reduced. Therefore, the lubricant hardly adheres or transfers to a light exit surface of a solid immersion lens even when recording and reproducing are carried out utilizing a floating optical head mounting the solid immersion lens. The lubricant bonding ratio can be further enhanced up to 80% or above by washing the lubricating layer 7 with a solvent after the lubricating layer 7 is heated or/and irradiated with UV.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium for performing recording and reproduction using a floating optical head and a method for manufacturing the same. An optical recording medium having enhanced seek resistance, and preventing or suppressing the transfer or adhesion of a lubricant of an optical recording medium to a slider surface of a floating optical head and a light exit surface of a solid immersion lens, and a method of manufacturing the same. About.

[0002]

2. Description of the Related Art With the advent of the multimedia age, optical recording media have been widely used as media capable of recording and reproducing a large amount of information such as music, moving images, and computer data. An optical recording medium is a read-only optical recording medium such as a CD or a laser disk that can only reproduce information,
It is classified into a write-once optical recording medium, such as a CD-R, on which recording can be performed only once, and a rewritable optical recording medium on which data can be rewritten and erased many times.

[0003] As one type of rewritable optical recording medium, for example, a magneto-optical recording medium is known. A magneto-optical recording medium generally has a structure in which a first dielectric layer, a magneto-optical recording layer, a second dielectric layer, a reflective layer, and a protective layer are sequentially laminated on a transparent substrate. The recording and reproduction are performed using the coil for use.

[0004]

In recent years, it has been demanded that the storage capacity of an optical recording medium be further increased with an increase in the amount of information to be handled. To meet this request,
There has been proposed a method of performing recording and reproduction using a floating head equipped with a solid immersion lens (SIL). According to this method, recording and reproduction can be performed with a smaller light spot diameter than in the related art, so that the recording density per unit area can be increased by about one digit as compared with the conventional magneto-optical recording medium.

[0005] When recording and reproducing using SIL,
The near-field light oozing from the IL can be used as the recording / reproducing light. Since the near-field light is attenuated at a distance of about １ ／ of the wavelength of the light, the distance between the SIL and the recording layer needs to be １ ／ or less of the wavelength of the recording / reproducing light. For example, when a red laser having a wavelength of 680 nm is used, the distance between the light emitting surface of the solid immersion lens and the recording layer is set to 170.
nm or less. In a conventional magneto-optical recording medium, since the thickness of the transparent substrate is about 1.2 mm, it is difficult to allow near-field light to reach the recording layer through the substrate. Therefore, when near-field light is used, a method in which light is incident from the side opposite to the substrate is adopted. Accordingly, the lamination order of the magneto-optical recording medium using near-field light is different from that of the conventional medium, and usually, a reflective layer, a first dielectric layer, a magneto-optical recording layer, and a second dielectric layer are formed on a transparent substrate. It has a structure in which layers are sequentially stacked. In addition, since recording and reproduction are performed using a floating optical head, when the floating optical head performs a seek operation,
The floating optical head comes into contact with the medium. For this reason, on the second dielectric layer of the magneto-optical recording medium, a protective layer and a lubricating layer for improving the seek resistance are formed in this order.

By the way, the present applicant has disclosed in Japanese Patent Application Laid-Open No. 11-76.
No. 57, an optical recording medium having a reflective layer, a recording layer, and a dielectric layer on a substrate and being irradiated with recording light or reproduction light from the dielectric layer side, wherein a self-lubricating An optical recording medium having a protective layer having a property and a lubricating layer thereon is disclosed. As a compound constituting this lubricating layer,
A perfluoropolyether having at least one hydroxyl group, a carboxyl group, an ester group, or a piperonyl group at at least one end of a molecule is described because of its high adsorption energy to a protective film made of carbon.

However, when the flying type optical head seeks on the magneto-optical recording medium, a part of the lubricant is vaporized by the heat of the laser beam and transferred to the light emitting surface of the SIL, or
As the IL slides on the lubricant, the lubricant directly
There is a risk of transfer or adhesion to the light exit surface of the IL. When the lubricant is transferred or adhered to the light exit surface of the SIL, the SIL
However, there is a problem that the optical characteristics of the recording medium cannot be properly recorded and reproduced. The following can be considered as the cause. That is, the lubricant of the optical recording medium according to the optical recording method using the SIL has high transparency, unlike the magnetic recording medium according to the magnetic recording method such as a magnetic tape and a magnetic disk, but is transferred to the light exit surface of the SIL. Alternatively, it is considered that the attached lubricant is thermally decomposed by the heat of the laser beam, changes its properties, and deteriorates the transparency. Therefore, in order to prevent the lubricant from being transferred or adhered to the light emitting surface of the SIL, a lubricant having a further improved adsorbability to the protective layer than the lubricant disclosed in Japanese Patent Application Laid-Open No. 11-7657 is used. It is desired to be applied on top.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to prevent or suppress the transfer of a lubricant to a light exit surface of an optical element such as an SIL. An object of the present invention is to provide an optical recording medium capable of realizing the used recording and reproduction.

Another object of the present invention is to provide an optical recording medium using a lubricant for a lubricating layer capable of maintaining high transparency without being thermally decomposed even when heated by light beam irradiation. It is in.

Still another object of the present invention is to provide a method for manufacturing an optical recording medium having a lubricating layer having high sliding resistance, in which a lubricant is hardly transferred to a light emitting surface of an optical element such as an SIL. Is to provide.

[0011]

According to a first aspect of the present invention, there is provided an optical recording medium comprising a reflective layer, a recording layer, a protective layer, and a lubricant layer composed of a lubricant on a substrate in this order. The lubricant bonding ratio of the lubricant to the protective layer is 60%.
To 100%.

FIG. 1 shows an example of the structure of an optical recording medium according to the present invention. The optical recording medium 10 has a reflective layer 2 on a substrate 1.
First dielectric layer 3, recording layer 4, second dielectric layer 5, protective layer 6
And a lubrication layer 7 in this order. As shown in FIG.
The lubricating layer 7 includes a bonding lubricating layer 8 existing on the protective layer 6 in combination with the protective layer, and a physically adsorbing lubricating layer 9 existing on the bonding lubricating layer 8 and not bonded to the protective layer. It is composed of Incidentally, regarding the lubricating layer, it is known that a conventionally used magnetic disk is also formed on the uppermost layer of the magnetic disk in order to reduce wear of the magnetic disk by the magnetic head. As a measure for expressing the degree of bonding between the lubricating layer and a surface (for example, a protective layer) on which the lubricating layer is coated, a lubricant bonding ratio is known. The lubricant bonding ratio is represented by a ratio of the bonding lubricating layer in the lubricating layer. In the present specification, in order to quantify the lubricant binding ratio, the thickness of the lubricating layer is set to A, and the base or the information recording medium including the lubricating layer and its coated surface is ultrasonically cleaned in a solvent for 30 seconds. When the thickness of the subsequent lubricating layer is B, the lubricant binding ratio is B / A × 100
%. According to a study by the inventor, it has been found that the lubricant binding ratio in a magnetic disk is usually 30% to 50%.

The optical recording medium according to the first aspect of the present invention is characterized in that the lubricant binding ratio of the lubricating layer is increased to 60% or more in consideration of the principle of recording / reproducing the optical recording medium with an optical head. . That is, since the lubricant binding ratio is 60% or more, the amount of the physically adsorbing lubricant on the binding lubricant is small, so that, for example, recording and reproduction using a floating optical head equipped with an SIL can be performed. Between the optical head and the recording surface
Even in the case of an optical recording / reproducing method in which recording / reproducing is performed very close to 00 nm or less, it is possible to prevent or suppress the physical adsorption lubricant from being transferred or adhered to the light exit surface of the SIL. Also, due to the combined lubricant component, S
Even if the floating optical head on which the IL is mounted seeks on the optical recording medium, the floating optical head does not directly contact the protective layer, and the durability of the optical recording medium can be further improved.

In the present invention, the lubricating layer has an alcohol group, a carboxyl group, an ester group, or a piperonyl group at one or both ends of the molecule, and has a molecular weight of 2,000 to 1,000.
It is preferable to use a zero perfluoropolyether lubricant. When the molecular weight is less than 2,000, the lubricating effect is insufficient, and it is easy to vaporize due to a rise in temperature. On the other hand, if the molecular weight exceeds 10,000, the viscosity of the lubricant increases and the coefficient of friction increases, making it difficult to slide the optical head on the optical recording medium satisfactorily. In addition, molecular weight 2
Since the thermal decomposition temperature of the 000 to 10000 perfluoropolyether lubricant is about 350 ° C., it does not show any light absorption for light in the visible light region even when used in an optical recording system. Therefore, the function as a lubricant can be exhibited without deteriorating the optical characteristics of the optical system.

In addition to the above lubricants, a perfluoropolyether having one or both terminal groups of the molecule having two or more hydroxyl groups can be used as the lubricating layer.
Such a perfluoropolyether lubricant has a molecular weight of 20
It is preferable to have a number of
_{OCH 2 CH (OH) CH 2} OCH 2 CF 2 O- (C
_{2 F 4 O) n - (} CF 2 O) m -CF 2 CH 2 OCH 2
Perfluoropolyether represented by CH (OH) CH ₂ OH can be used. In the formula, n and m are appropriately selected such that the molecular weight of the perfluoropolyether is in the range of 2,000 to 10,000, and for example, the values of n and m may be substantially equal.

In the present invention, in order to further enhance the durability by combining the lubricant with the protective layer, after forming the lubricating layer on the protective layer, the lubricating agent is heated within a temperature range of 50 ° C. to 120 ° C., or At a wavelength of 18 in the atmosphere or in an inert atmosphere.
It is preferable to irradiate ultraviolet rays having a wavelength of 5 nm to 254 nm, for example, ultraviolet rays having a wavelength of 185 nm and / or 254 nm which can be used at present. In addition, the combined use of heating and ultraviolet irradiation can further promote the bonding of the lubricant to the protective layer.

In the present invention, in order to minimize transfer or adhesion of the lubricant to the solid immersion lens, it is preferable that the lubricant binding ratio is 80% or more. In order to make the lubricant binding rate 80% or more, for example, after forming a lubricating layer on the protective layer, it may be washed by using a solvent in addition to heating or irradiation with ultraviolet rays.

According to a second aspect of the present invention, on a substrate:
In an optical recording medium including a reflective layer, a recording layer, a protective layer, and a lubricant layer composed of a lubricant in this order, the lubricant is perfluoropolyether, and at least one molecular terminal group of the perfluoropolyether is used. Has an optical recording medium having two or more hydroxyl groups.

The optical recording medium according to the second aspect of the present invention comprises:
Considering the principle of recording / reproducing of an optical recording medium by a floating type optical head, it is characterized in that a perfluoropolyether having one or both terminal groups of a molecule having two or more hydroxyl groups is used as a lubricant molecule. . A perfluoropolyether having two or more hydroxyl groups at one or both terminal groups of a molecule has one hydroxyl group at one or both terminal groups as disclosed in JP-A-11-7657. Compared with perfluoropolyether, the number of functional groups of the lubricant molecule is twice or more, so that the adsorption force to the carbon protective film used as the protective layer is improved about twice or more.
Sliding resistance is increased by improving the adsorption force of the lubricant molecules,
Even if the seek is performed, the coefficient of friction of the medium surface can be kept low, and the occurrence of damage (sliding scratch) on the medium surface can be suppressed.

The above-mentioned perfluoropolyether lubricant used in the present invention preferably has a molecular weight of 2,000 to 10,000. When the molecular weight is 2000 or more,
The lubricating effect is further enhanced, and the vaporization rate when the temperature rises can be reduced. By setting the molecular weight to less than 10,000, an increase in the coefficient of friction due to an increase in the viscosity of the lubricant can be suppressed, and good sliding characteristics of the floating optical head on the optical recording medium can be secured.

As the above perfluoropolyether lubricant,
And the main chain is-(C₂F₄O)_n− (CF₂O)_m-
In which both terminal groups of the molecule each have two OH groups.
Fluoropolyethers such as HO-CH₂CH (O
H) CH₂OCH₂CF₂O- (C₂F₄O)_n− (C
F₂O)_m-CF₂CH₂OCH₂CH (OH) CH ₂
Perfluoropolyethers represented by OH are preferred.
This perfluoropolyether is, for example, Audimon
Available under the trade name Fomblin-Z-Tetraol
You. In the formula, n and m are a part of perfluoropolyether.
Suitable to be in the range of 2,000 to 10,000.
For example, the values of n and m may be substantially equal.

As another example of the above-mentioned perfluoropolyether lubricant, a perfluoropolyether having a main chain of F (C ₃ F ₆ O) _p − and one end group of a molecule having two OH groups is provided. ethers, for _{example, F (C 3 F 6 O} ) p -C 2
F ₄ CH ₂ OCH ₂ CH (OH) CH ₂ OH or F (C
₃ F _{6 O)} a perfluoropolyether represented by _{p -C 2 F 4 CH (OH} ) 2 is preferred. In the formula, P is appropriately selected such that the molecular weight of the perfluoropolyether is in the range of 2,000 to 10,000, and for example, the values of n and m may be substantially equal.

In the optical recording medium according to the second aspect of the present invention, like the optical recording medium according to the first aspect, a lubricant is combined with the protective layer to further enhance the durability, so that the lubricant is formed on the protective layer. After forming the lubricating layer, the lubricating layer is heated at a temperature of 50 ° C. to 120 ° C. or in an inert atmosphere at a wavelength of 185
Ultraviolet light of nm to 254 nm, for example, ultraviolet light of 185 nm and / or 254 nm which can be used at present, can be irradiated.

In the optical recording medium according to the second aspect of the present invention, the reason that it is desired to minimize the transfer or adhesion of the lubricant on the optical recording medium to the slider of the flying optical head and the light emitting surface of the SIL. From 60%
More preferably, it is 80%. By controlling the heat treatment temperature and treatment time, or ultraviolet irradiation time, 60
% To 80% of the lubricant binding ratio can be obtained.

The protective layer of the optical recording medium according to the first and second aspects of the present invention may be made of carbon. Carbon is
It may contain at least one element selected from the group consisting of hydrogen, nitrogen, silicon and fluorine. For example, it can be composed of hydrogen-containing carbon, nitrogen-containing carbon, silicon-containing carbon, fluorine-containing carbon, carbon containing hydrogen and nitrogen, carbon containing hydrogen and fluorine, and carbon containing hydrogen, fluorine and silicon. By using these materials, the floating type optical head slides smoothly on the optical recording medium, so that formation of sliding scratches on the medium surface is prevented or suppressed. The thickness of the protective film is 5 nm to 100 n.
m is preferable. If it is less than 5 nm, the coverage is not sufficient, and if it exceeds 100 nm, the distance between the recording layer and the optical head increases, so that recording and reproduction using near-field light cannot be realized.

The optical recording medium of the present invention is a CD, CD-RO
M, like a DVD-ROM, whether there are uneven pits or holes,
Laser light is used to open a hole in a read-only optical recording medium that reproduces information based on the difference in reflectance between the crystalline phase and the amorphous layer, or an inorganic layer such as an organic dye layer or a Te compound such as a CD-R. Write-once optical recording media for recording information with a gap
A magneto-optical recording medium having a recording layer of an alloy layer of a rare earth metal and a transition metal such as TbFeCo or DyFeCo, and a recording film such as a Ge alloy or an In alloy are reversibly switched between a crystalline phase and an amorphous layer by light irradiation. Any optical recording medium such as a rewritable optical recording medium such as a phase-change optical recording medium that can be changed to an optical recording medium is targeted.

The substrate used in the optical recording medium of the present invention comprises:
In addition to resins such as polycarbonate, polyolefin, polymethyl acrylate, polystyrene, and nylon, glass substrates, silicon, thermally oxidized silicon, Al, T
A metal disk substrate such as i can be used.

According to a third aspect of the present invention, on a substrate:
In a method of manufacturing an optical recording medium including a reflective layer, a recording layer, a protective layer, and a lubricating layer in this order, after applying a lubricant on the protective layer, the lubricant bonding ratio of the lubricant to the protective layer is 60%. A method for producing an optical recording medium is provided, wherein a lubricating layer is formed by performing at least one of heating and ultraviolet irradiation so that the amount becomes 100% or less.

In the manufacturing method of the present invention, after applying a lubricant on the protective layer, a lubricant layer is formed by heating or irradiating ultraviolet rays, so that the lubricant bonding ratio of the lubricant layer can be adjusted to 60% to 100%. . Heating and UV irradiation can be used together,
This further promotes the bonding of the lubricant to the protective layer. In the present invention, the temperature for heating is 50 ° C to 120 ° C.
It is preferable to carry out in the range of ° C. When the temperature is lower than 50 ° C., the lubricant binding reaction on the protective layer does not sufficiently proceed, which is not preferable. When the temperature exceeds 120 ° C., the substrate is deformed by heat, which is not preferable.

The lubricant applied on the protective layer is, for example,
Fluoropolyethers can be used,
As a fluoropolyether, at least one molecule
It is preferable that the terminal group has two or more hydroxyl groups. Ma
The molecular weight of the perfluoropolyether is 2,000 to 1,
0000 is preferred. Specifically, HO-C
H₂CH (OH) CH₂OCH₂CF₂O- (C₂F₄
O)_n− (CF₂O) _m-CF₂CH₂OCH₂CH
(OH) CH₂Perfluoropolyate represented by OH
Are preferred. In the formula, n and m are
The molecular weight of the ether is in the range of 2,000 to 10,000
, For example, the values of n and m are substantially equal
May do it.

The ultraviolet rays used for the irradiation of the ultraviolet rays include ultraviolet rays having a wavelength of 185 nm to 254 nm, for example,
Ultraviolet rays having a wavelength of 185 nm or 254 nm that can be used at the present time can be used, and irradiation can be performed using these two types of ultraviolet rays in combination. When ultraviolet irradiation is performed in the air, particularly in the case of ultraviolet light having a wavelength of 185 nm, active oxygen is generated and the lubricant is decomposed. Therefore, the ultraviolet irradiation is preferably performed in an inert atmosphere. As the inert atmosphere, for example, a nitrogen atmosphere, an argon atmosphere, or a helium atmosphere is preferable.

In the production method of the present invention, a solvent is used
It is preferable to wash the optical recording medium by using the above method. This ensures
Physisorbent lubricant that did not bind to the protective layer was removed
The amount of the physisorbing lubricant in the lubrication layer decreases,
The proportion of binding lubricant will be relatively increased. sand
In other words, as a result, the lubricant binding rate is increased.
You. In addition, the solvent used when cleaning the optical recording medium and
The perfluorooctane (C₈F₁₈) And perf
Fluorohexane (C₆F₁₄), C₄F₉OCH ₃(3
(Available under the trade name HFE-7100 from Company M), C
₄F₉OC₂H₅(HFE-7200 trade name from 3M)
), Galden (Audimont), etc.
Can be used.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and examples of the optical recording medium of the present invention will be specifically described below. First, an embodiment of the optical recording medium according to the first aspect of the present invention will be described.

Production Example 1 In this production example, a magneto-optical recording medium 20 having a sectional structure shown in FIG. 2 was produced. The magneto-optical recording medium 20 has a structure in which a reflective layer 2, a first dielectric layer 3, a recording layer 4, a second dielectric layer 5, and a protective layer 6 are sequentially laminated on a substrate 1. A method for manufacturing the magneto-optical recording medium 20 having such a structure will be described below.

First, a stamper on which a concavo-convex pattern corresponding to a land and a groove was formed was loaded into a mold of an injection molding machine, and a polycarbonate resin material was injection-molded in the mold to produce a polycarbonate substrate 1. Next, the obtained polycarbonate substrate 1 was loaded into a DC magnetron sputtering apparatus, and AlTi as a reflective layer 2 was formed on the polycarbonate substrate 1 to a thickness of 50 nm by sputtering. Next, the first
SiNx as the dielectric layer 3 was formed in a thickness of 30 nm, and TbFeCo as the recording layer 4 was sequentially formed in a thickness of 20 nm. Next, SiN as the second dielectric layer 5
x was formed with a thickness of 80 nm, and carbon as the protective layer 6 was formed with a thickness of 10 nm. The sputtering conditions for sputtering these layers 2 to 6 are as follows. In forming the reflective layer 2, AlT is used as a target material.
5 × 1 Ar gas as sputtering atmosphere using i-alloy
0 ^- used in ³ Torr pressure. In forming the first dielectric layer 3 and the second dielectric layer 5, Si is used as a target material.
Ar + N ₂ gas is used as a sputtering atmosphere at 7 × 1
0 used in ^-3 Torr pressure. In forming the recording layer 4, TbFeCo was used as a target material, and Ar gas was used at a pressure of 5 × 10 ⁻³ Torr as a sputtering atmosphere. In forming the protective layer 6, carbon is used as a target material, and Ar gas is used as a sputtering atmosphere.
It was used at a pressure of × 10 ⁻³ Torr. The magneto-optical recording medium thus obtained is referred to as Sample 1.

Production Example 2 The procedure of Production Example 1 was repeated except that Ar + H ₂ gas was used as a sputtering atmosphere gas when sputtering the protective layer 6 and a hydrogen-containing carbon protective layer was formed as the protective layer 6. Thus, a magneto-optical recording medium was manufactured. The magneto-optical recording medium thus obtained is referred to as Sample 2.

Production Example 3 In Production Example 1, Ar + CH ₄ gas was used as a sputtering atmosphere gas when sputtering the protective layer 6.
A magneto-optical recording medium was manufactured in the same manner as in Manufacturing Example 1 except that a hydrogen-containing carbon protective layer was formed as a film. The magneto-optical recording medium thus obtained is referred to as Sample 3.

Production Example 4 The procedure of Production Example 1 was repeated except that Ar + N ₂ gas was used as a sputtering atmosphere gas when sputtering the protective layer 6, and a nitrogen-containing carbon protective layer was formed as the protective layer 6. Thus, a magneto-optical recording medium was manufactured. The magneto-optical recording medium thus obtained is referred to as Sample 4.

Production Example 5 A production example except that Ar + N ₂ + H ₂ gas was used as a sputtering atmosphere gas when sputtering the protective layer 6 in Production Example 1, and a hydrogen and nitrogen-containing carbon protective layer was formed as the protective layer 6. A magneto-optical recording medium was manufactured in the same manner as in Example 1. The magneto-optical recording medium thus obtained is referred to as Sample 5.

Production Example 6 Plasma CVD using 13.56 MHz high frequency using methane as a monomer gas and hydrogen as a carrier gas
A magneto-optical recording medium was produced in the same manner as in Production Example 1, except that a hydrogen-containing carbon (diamond-like carbon) protective layer was formed as a protective layer 6 on the second dielectric layer by the method. The magneto-optical recording medium thus obtained is referred to as Sample 6.

Production Example 7 Samples 1 to 6 were produced in the same manner as in Production Examples 1 to 6, and the main chain was F (C ₃ F ₆ O) _n- A lubricating layer was formed by applying a perfluoropolyether lubricant a having an alcohol group and an average molecular weight of 7000 with a dip coater to a thickness of 2 nm.

Production Example 8 Samples 1 to 6 were produced in the same manner as in Production Examples 1 to _{6. On} the protective layer of each sample, the main chain was F (C ₃ F ₆ O) _n- Group is carboxyl, average molecular weight 4000
Was applied with a dip coater to a thickness of 2 nm to form a lubricating layer.

Production Example 9 Samples 1 to 6 were produced in the same manner as in Production Examples 1 to 6, and the main chain was F (C ₃ F ₆ O) _n — Group is an ester (—C ₂ F ₄ COOC
_{H 3, -C 2 F 4 CH} 2 COOCH 3), an average molecular weight 4
000 perfluoropolyether lubricant c was applied with a dip coater to a thickness of 2 nm to form a lubricating layer.

Production Example 10 Samples 1 to 6 were produced in the same manner as in Production Examples 1 to 6, and the main chain was F (C ₃ F ₆ O) _n — A lubricating layer was formed by applying a perfluoropolyether lubricant d having a piperonyl group and an average molecular weight of 4400 with a dip coater to a thickness of 2 nm.

Production Example 11 Samples 1 to 6 were produced in the same manner as in Production Examples 1 to 6, and the main chain was-(C ₂ F ₄ O) _n (C
F ₂ O) _m −, a terminal functional group of alcohol, and a perfluoropolyether lubricant e having an average molecular weight of 5,000
A lubricating layer was formed by coating with a dip coater to a thickness of nm.

Production Example 12 Samples 1 to 6 were produced in the same manner as Production Examples 1 to 6, and the main chain was-(C ₂ F ₄ O) _n (C
F ₂ O) _m — and the terminal functional group is an ester (—C ₂ F)
₄ COOCH ₃ , —C ₂ F ₄ CH ₂ COOCH ₃ ), a perfluoropolyether lubricant f having an average molecular weight of 4000
Was applied with a dip coater to a thickness of 2 nm to form a lubricating layer.

Production Example 13 Samples 1 to 6 were produced in the same manner as Production Examples 1 to 6, and the main chain was-(C ₂ F ₄ O) _n (C
F 2 _O) is m-, terminal functional groups are carboxyl, to form a lubricant layer by applying the average molecular weight of 4,000 perfluoropolyether lubricant dip coater at a thickness of 2nm to g of.

Production Example 14 Samples 1 to 6 were produced in the same manner as Production Examples 1 to 6, and the main chain was-(C ₂ F ₄ O) _n (C
F ₂ O) _m −, a perfluoropolyether lubricant h having a terminal functional group of piperonyl and an average molecular weight of 3,200
A lubricating layer was formed by coating with a dip coater to a thickness of nm.

Lubricants a to h used in Production Examples 7 to 14
Are summarized in Table 1 below, and the correspondence between the medium and the lubricant used in Production Examples 1 to 14 is summarized in Table 2 below.

[0050]

[Table 1]

[0051]

[Table 2]

Example 1 Each magneto-optical recording medium produced in the same manner as in Production Examples 7 to 14 was placed in the air at 100 ° C. in a thermostat at 100 ° C.
Heat treatment was performed for 2 hours.

Example 2 The surface of each of the magneto-optical recording media produced in the same manner as in Production Examples 7-14 was irradiated with ultraviolet rays for 15 minutes using a low-pressure mercury lamp generating ultraviolet rays having a wavelength of 254 nm. The irradiation power of the ultraviolet light was 200W.

Example 3 The surface of each magneto-optical recording medium produced in the same manner as in Production Examples 7 to 14 was irradiated with ultraviolet light for 15 minutes in a nitrogen atmosphere using a low-pressure mercury lamp generating ultraviolet rays having wavelengths of 185 nm and 253 nm. Was irradiated. UV irradiation power is 2
00W.

Example 4 The surface of each magneto-optical recording medium produced in the same manner as in Production Examples 7 to 14 was exposed to air using an infrared lamp in the air.
While heating to 00 ° C., ultraviolet rays were irradiated for 15 minutes using a low-pressure mercury lamp that generates ultraviolet rays having a wavelength of 254 nm.
The irradiation power of the ultraviolet light was 200W.

Example 5 The surfaces of the respective magneto-optical recording media produced in the same manner as in Production Examples 7 to 14 were heated to 100 ° C. using an infrared lamp in a nitrogen atmosphere while the wavelengths of 185 nm and 253 nm were used.
UV light was irradiated for 15 minutes using a low-pressure mercury lamp that generates UV light of m. The irradiation power of the ultraviolet light was 200W. Thus, a magneto-optical recording medium according to the first aspect of the present invention was obtained.

[Measurement of Lubricant Layer Thickness and Calculation of Lubricant Bonding Ratio] The magneto-optical recording media manufactured in Examples 1 to 5 were subjected to X-ray photoelectron spectroscopy (XPS) as follows. Was measured and the lubricant binding ratio was calculated. First, two 5 mm × 5 mm analysis samples were cut out from each magneto-optical recording medium as analysis samples at a position 40 mm in the radial direction from the center, and one of the analysis samples was analyzed by XPS as it was, and the lubricant film thickness was measured. Was measured. The other sample for analysis was an ultrasonic cleaner (Model, manufactured by Iuchi).
(VS-100). In the ultrasonic cleaning, perfluorooctane: C ₈ F is used as a solvent.
Using No. ₁₈ , ultrasonic cleaning was performed at a frequency of 50 kHz and an output of 100 W for 30 seconds. Next, XPS analysis was performed on each analysis sample after the ultrasonic cleaning, and the thickness of the lubricating layer was measured. The measurement results are shown in Table 3 below. In Table 3, the thickness of the lubricating layer before ultrasonic cleaning was A, the thickness of the lubricating layer after ultrasonic cleaning was B, and the lubricant binding ratio was B / A × 1.
It was defined as 00%. The lubricant bonding rates of the lubricating layers of the magneto-optical recording media of Examples 1 to 5 were all 60% or more.

[0058]

[Table 3]

COMPARATIVE EXAMPLE 1 For each magneto-optical recording medium manufactured in the same manner as in Manufacturing Examples 7-14, no post-processing was performed, and XPS was used in the same manner as in the magneto-optical recording medium obtained in the above embodiment. The thickness of the lubricating layer was measured to calculate the lubricant binding ratio. The lubricant binding ratio was a low value of about 20%. Table 3 shows the results.

Comparative Example 2 Sample 1 was produced in the same manner as in Production Example 1, and the protective layer
On top, oleic acid (C ₁₈H₃₄O₂) Dipco
A lubricating layer was formed by coating with a lubricator. Obtained magneto-optics
Regarding the recording medium, the magneto-optical recording medium obtained in the above example was used.
Lubricate by measuring the thickness of the lubrication layer using XPS as well as the body
The agent binding rate was calculated. Lubricant binding rate is low at around 30%
Value. Table 3 shows the results.

Examples 6 to 10 Rinsing treatment was performed by immersing the magneto-optical recording media obtained in Examples 1 to 5 in a bath filled with a solvent (perfluorooctane: C ₈ F ₁₈ ) for 3 minutes. . Table 4 shows the types of media used in Examples 6 to 10, respectively.

[0062]

[Table 4]

For each of the rinsed magneto-optical recording media of Examples 6 to 10, the thickness of the lubricating layer was measured using XPS in the same manner as in the magneto-optical recording media obtained in the above Examples, and the lubricant was bonded. The rate was calculated. Table 5 shows the results. In each of the magneto-optical recording media of Examples 6 to 10, the lubricant bonding ratio of the lubricating layer was as high as 80% or more. This is considered to be because the physical adsorption lubricant present on the surface of the lubricating layer was removed because the rinsing treatment was performed in advance with the solvent, and the lubricant binding rate was increased.

[0064]

[Table 5]

Each of the magneto-optical recording media obtained in Examples 1 to 10 and Comparative Examples 1 and 2 has a diameter of 80 μm.
A continuous 24-hour recording / reproducing test was performed while performing a seek using a floating slider in which a solid immersion lens made of zirconia having a refractive index of 2.2 was embedded. The flying height of the flying slider from the medium was maintained at about 100 nm. After the completion of the recording / reproducing test, the light exit surface of the solid immersion lens (SIL) was examined for stains using an optical microscope. Table 6 shows the results.

[0066]

[Table 6]

The transfer of the lubricant to the SIL was slight in the magneto-optical recording medium (Examples 1 to 5) subjected to the heat treatment or the ultraviolet treatment. On the other hand, a magneto-optical recording medium not subjected to heat treatment or ultraviolet irradiation treatment (Comparative Examples 1 and 2)
In case (1), it was found that a large amount of the lubricant was transferred to the light exit surface of the SIL. Further, a magneto-optical recording medium subjected to a rinsing treatment after the heat treatment or the ultraviolet irradiation treatment (Examples 6 to 6)
In the case of 10), almost no lubricant transfer to the SIL was observed. This is probably because the physisorbing lubricant remaining on the surface layer of the lubricating layer was removed by the rinsing treatment.

[Measurement of Thermal Decomposition Temperature] In the magneto-optical recording / reproducing method, since the medium is heated by light beam irradiation, the lubricant is required to have heat resistance. In order to investigate the effect of thermal decomposition of the lubricant by light beam irradiation, a thermobalance was used for the perfluoropolyether lubricants a to h of Production Examples 7-14 and the lubricant (oleic acid) used in Comparative Example 2. Then, the temperature at which thermal decomposition started (pyrolysis temperature) was measured. As a result of the measurement, the thermal decomposition temperatures of the perfluoropolyether lubricants a to h of Production Examples 7 to 14 were all 350 ° C. or higher.
On the other hand, the thermal decomposition temperature of oleic acid used in Comparative Example 2 was 200 ° C. During recording and reproduction, the magneto-optical recording medium
Normally, since heating is performed to 280 ° C. to 300 ° C. by light beam irradiation, in the magneto-optical recording medium of Comparative Example 2 using oleic acid as a lubricant, thermal decomposition of the lubricant occurs,
It is considered that optical characteristics at the time of recording / reproducing are deteriorated due to light absorption.

[Random Seek Test] Next, Example 1
5 and Comparative Examples 1 and 2 were subjected to a random seek test. The test was evaluated based on the increase in the number of defects after random seek. FIG. 3 shows the optical system of the device used for the measurement. FIG. 3 shows an optical system in the case of a magneto-optical recording device. In FIG. 3, as the fixed optical system, the same optical system of a drive for recording and reproducing an ordinary magneto-optical recording medium can be used. That is, the laser light emitted from the laser light source 57 is
9b and the beam splitter 60, and the mirror 70,
After being reflected by 69, it is incident on the objective lens 71, and is further condensed by the solid immersion lens (SIL) 100 to focus on the bottom surface of the SIL 100. The light oozing out from the bottom surface of the SIL 100 enters from the lubricating layer side of the magneto-optical recording medium 400, reaches the recording layer, and forms a magnetic mark on the recording layer according to a recording signal. At the time of recording, a recording magnetic field is applied to the magneto-optical recording medium 400 by the magnetic coil 104, and recording can be performed by any of the optical modulation method, the magnetic field modulation method, and the optical magnetic field modulation method.

At the time of reproduction, the reflected light from the magneto-optical recording medium 400 is reflected by the mirrors 69 and 70, then reflected by the beam splitter 60 and split by the beam splitter 61 into light directed to two beam splitters 64 and 65. Is done.
The reflected light that has entered the beam splitter 65 is further split there and enters the focusing detection detector 68c and the tracking signal detection detector 68d, respectively. The reflected light that has passed through the half-wave plate 63 and the lens 67 and entered the beam splitter 64 enters photodetectors 68a and 68b that detect light of polarization components orthogonal to each other, and detects a reproduced signal. .

The random seek test method uses the 10
The increase in the number of defects before and after the random seek for 000 times was measured. For the defect, a pattern composed of a relatively long recording mark having a mark length of 1 μm is written on all the tracks (12,500 tracks) having a radius of 30 to 40 mm, and the amplitude of the magneto-optical signal obtained when reproducing the pattern becomes 65% or less. The part was defective. In order to prevent dust from the surrounding environment from adhering to the medium during the measurement and forming a defect, the measurement is performed in a measurement room with a cleanness of 100 and the optical recording device itself used for the measurement is placed in a clean booth. To measure the defects. The number of increased defects was determined according to the following equation.

The number of increased defects = (the number of defects after random seek)-(the number of defects before random seek)

Table 7 shows the results of random seek tests (increased number of defects) of Examples 1 to 5 and Comparative Examples 1 and 2.

[0074]

[Table 7]

In the random seek test of the magneto-optical recording media of Comparative Examples 1 and 2, the optical head after 100,000 random seeks was observed. As a result, a large amount of lubricant was adhered to the light emitting surface of the SIL. . As can be seen from the results of the random seek test shown in Table 7, the defect rates of the magneto-optical recording media of Comparative Examples 1 and 2 in which a large amount of the lubricant was transferred to the light exit surface of the SIL also increased. . In particular, in the magneto-optical recording medium of Comparative Example 2, the defect rate was significantly increased because the lubricant adhering to the light emitting surface of the optical head was thermally decomposed by heating by laser light irradiation, and It is considered that the transmittance was deteriorated.

Next, an embodiment of the optical recording medium according to the second aspect of the present invention will be specifically described.

Example 11 Samples 1 to 6 were produced in the same manner as in Production Examples 1 to 6, and the main chain was-(C ₂ F ₄ O) _n- on the protective layer of each sample.
(CF ₂ O) _m −, a perfluoropolyether lubricant i of the following formula having two hydroxyl groups at both molecular terminal groups: H
_{OCH 2 CH (OH) CH 2} OCH 2 CF 2 O- (C
_{2 F 4 O) n - (} CF 2 O) m -CF 2 CH 2 OCH 2
CH (OH) CH ₂ OH was applied with a dip coater to a thickness of 2 nm to form a lubricating layer. The perfluoropolyether lubricant i of the above formula has an average molecular weight of 4000
Met.

Example 12 Samples 1 to 6 were produced in the same manner as in Production Examples 1 to _{6. On} the protective layer of each sample, the main chain was F (C ₃ F ₆ O) _p − perfluoropolyether lubricant _j of the formula having two hydroxyl groups at the terminal based _{on: F (C 3 F 6 O} ) p -C
₂ F ₄ CH ₂ OCH ₂ CH (OH) CH ₂ OH at 2 nm
A lubricating layer was formed by coating with a dip coater at a film thickness of The perfluoropolyether lubricant j of the above formula is
The average molecular weight was 7,000.

COMPARATIVE EXAMPLE 3 Mainly on the protective layer of the magneto-optical recording medium obtained in Production Examples 1 to 6.
When the chain is-(C₂F₄O) _n− (CF₂O)_m-Minutes
Having one hydroxyl group at each terminal of the
-Fluoropolyether: HO-CH₂CF₂O- (C
₂F₄O)_n− (CF₂O)_m-CF₂CH₂From OH
Lubricant with a thickness of 2 nm using a dip coater
Applied. This perfluoropolyether is
The product name was Fomblin-Z-DOL. this
The average molecular weight of the perfluoropolyether lubricant is 400
It was 0.

Comparative Example 4 The main chain was F (C ₃ F ₆ O) _p − on the protective layer of the magneto-optical recording medium obtained in Production Examples 1 to 6, and one hydroxyl group was present at one molecular terminal. Perfluoropolyether: F (C ₃ F ₆
O) to form a lubricating layer is applied by _p -C ₂ F ₄ CH ₂ OH lubricant dip coater with a film thickness of 2nm a made of. The average molecular weight of this perfluoropolyether is 70
00.

[Measurement of Lubricating Layer Thickness and Calculation of Lubricant Bonding Ratio] The lubricating layer thickness of each of the magneto-optical recording media manufactured in Examples 11 and 12 and Comparative Examples 3 and 4 was determined in Examples 1 to 5.
As in the case of measuring the magneto-optical recording medium, the measurement was performed using XPS to calculate the lubricant binding ratio. Table 8 shows the measurement results.

[0082]

[Table 8]

The lubricant used in the magneto-optical recording media of Examples 11 and 12 has two hydroxyl groups at one terminal group or both terminal groups of the molecule, and therefore has a large adsorbing power to the carbon protective film and a high lubricant binding ratio. Showed a value of 40% or more.
On the other hand, the lubricants used in the magneto-optical recording media of Comparative Examples 3 and 4 have only one hydroxyl group at one end group or both end groups of the molecule, and therefore have a low adsorptivity to the carbon protective film and have a low lubricant binding rate. Was as low as about 20%.

[Sliding Test Conditions and Test Environment] Next, sliding tests using steel balls were performed on the magneto-optical recording media obtained in Examples 11 and 12 and Comparative Examples 3 and 4. . The slider used is a 1/4 inch diameter high carbon C
r steel ball, load 5g, sliding width 2cm, average sliding speed 2m
/ Min (50 cycles / min). The test environment was set at 25 ° C. and 35% RH. Table 9 summarizes the friction coefficient of the magneto-optical recording media obtained in Examples 11 and 12 and Comparative Examples 3 and 4 after sliding for 50 cycles, and the number of times of sliding until a scratch is formed on the surface of the medium. Shown.

[0085]

[Table 9]

From the results shown in Tables 8 and 9, Examples 3 and 4 show that the adsorptivity of the lubricant molecules is large and the lubricant binding rate is high.
Of the magneto-optical recording media of Comparative Examples 3 and 4, which have a small adsorbing force of the lubricant molecules and a low lubricant binding ratio, have a reduced friction coefficient after sliding for 50 cycles. It can be seen that the slidability is significantly improved.

Example 13 Each magneto-optical recording medium produced in the same manner as in Examples 11 and 12 was placed in an air atmosphere using a thermostat.
Heat treatment was performed at 0 ° C. for 2 hours.

Example 14 The surface of each of the magneto-optical recording media manufactured in the same manner as in Examples 11 and 12 was coated with a wavelength of 254 nm in an air atmosphere.
UV light was irradiated for 5 minutes using a low-pressure mercury lamp that generates UV light. The irradiation power of the ultraviolet light was 200W.

Example 15 The surface of each magneto-optical recording medium manufactured in the same manner as in Examples 11 and 12 was placed in a nitrogen atmosphere at a wavelength of 185 nm.
Ultraviolet rays were irradiated for 5 minutes using a low-pressure mercury lamp generating ultraviolet rays of m and 254 nm. The irradiation power of the ultraviolet light was 200W.

Example 16 Ultraviolet rays having a wavelength of 254 nm were generated on the surface of each magneto-optical recording medium manufactured in the same manner as in Examples 11 and 12, while being heated to 100 ° C. using an infrared lamp in an air atmosphere. Ultraviolet irradiation was performed for 5 minutes using a low-pressure mercury lamp. The irradiation power of the ultraviolet light was 200W.

Example 17 The surface of each of the magneto-optical recording media produced in the same manner as in Examples 11 and 12 was heated to 100 ° C. using an infrared lamp in a nitrogen atmosphere while the wavelengths of 185 nm and 2
Using a low-pressure mercury lamp that generates 54 nm ultraviolet light, 5
UV light was applied for a minute. UV irradiation power is 200W
Met. Thus, a magneto-optical recording medium according to the second aspect of the present invention was obtained.

The thickness of the lubricating layer of the magneto-optical recording medium obtained in Examples 13 to 17 was measured by using XPS in the same manner as when measuring the magneto-optical recording medium obtained in Examples 1 to 5. The lubricant binding rate was calculated. Table 10 shows the results. Example 1
It can be seen that each of the magneto-optical recording media Nos. 3 to 17 has a lubricant binding rate of 60% or more.

[0093]

[Table 10]

For each of the magneto-optical recording media obtained in Examples 11 to 17, a zirconia solid immersion lens (SIL) having a diameter of 80 μm and a refractive index of 2.2 was used.
The recording / reproducing test was performed continuously for 24 hours while performing a seek operation using a floating slider equipped with. The flying height of the flying slider from the surface of the medium was maintained at about 100 nm. After the recording / reproducing test, SIL was performed using an optical microscope.
Condition of the light exit surface and scratching (sliding) of the media surface
The condition of the wound was observed.

Transfer or adhesion of the lubricant to the SIL was confirmed for the magneto-optical recording medium (Examples 13 to 17) in which the heat treatment or the ultraviolet irradiation treatment was performed to increase the bonding ratio of the lubricant to 60% to 100% (Examples 13 to 17). The number of scratches on the medium was 20 or less. On the other hand, a magneto-optical recording medium not subjected to heat treatment or ultraviolet irradiation treatment (Examples 11 and 1)
In 2), although the scratch on the medium is small, a small amount of lubricant
It was found that L was transferred or attached to a part of the light emission of L. The lubricant coupling ratio of the magneto-optical recording media of Examples 11 and 12 is about 40% as shown in Table 8, which is smaller than the magneto-optical recording media of Examples 13 to 17 (lubricant coupling ratio of 60% or more). Therefore, many physisorbing lubricant layers exist.
Therefore, it is considered that a certain amount of lubricant was transferred or attached to the slider surface of the flying head or the light emitting surface of the SIL. The results are summarized in Table 11.

[0096]

[Table 11]

Although the optical recording medium of the present invention and the method of manufacturing the same have been described in detail, the optical recording medium of the present invention is not limited to a magneto-optical recording medium, but may be a phase-change optical recording medium or an organic dye. Can be applied to any optical recording medium such as a write-once optical recording medium or a read-only optical recording medium having a recording layer. For example, in the case of a phase-change type optical recording medium, the medium configuration is such that a reflective layer, a dielectric layer, a recording layer, a dielectric layer, a protective film, and a lubricating layer according to the present invention are sequentially provided on a substrate. Specifically, the substrate / AlTi / Z
It can be _{nS + SiO 2 / GeSbTe / ZnS} + SiO 2 / carbon / lubricant.

[0098]

According to the optical recording medium according to the first aspect of the present invention, a floating type optical head having an SIL is provided by forming a lubricating layer having a lubricant binding rate of 60% to 100% on a protective layer. When performing recording and reproduction using the SIL, the transfer or adhesion of the lubricant to the light exit surface of the SIL is prevented or suppressed, and recording and reproduction using the SIL can be realized.

In the optical recording medium according to the second embodiment of the present invention, the carbon protective film is formed by using a perfluoropolyether having a molecular weight of 2,000 to 10,000 having two or more hydroxyl groups at one end or both ends of the molecule as a lubricant. As a result, the sliding resistance of the optical recording medium can be increased. Therefore, it is possible to prevent the lubricant from being transferred or adhered to the slider surface and the light emitting surface of the floating type optical head.

In the method of manufacturing an optical recording medium according to the present invention, a lubricant is applied onto the protective layer, and then heated or irradiated with ultraviolet rays so that the lubricant bonding ratio of the lubricating layer is 60% or more. The manufactured optical recording medium can perform recording and reproduction without damaging the optical recording medium even after performing continuous recording and reproduction for 24 hours. Further, by washing with a solvent in addition to heating and irradiation with ultraviolet rays, a lubricant binding rate of 80% or more could be achieved. Therefore, the method of the present invention is extremely suitable as a method for manufacturing an optical recording medium on which recording and reproduction are performed using a floating optical head equipped with an SIL.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a cross-sectional structure of a magneto-optical recording medium on which recording and reproduction are performed using a flying optical head.

FIG. 2 is a diagram schematically showing a cross-sectional structure of a magneto-optical recording medium manufactured in Manufacturing Example 1.

FIG. 3 is a diagram schematically illustrating an optical system of a magneto-optical recording device used for measurement in a random seek test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Reflection layer 3 1st dielectric layer 4 Recording layer 5 2nd dielectric layer 6 Protective layer 7 Lubrication layer 8 Coupling lubrication layer 9 Physical adsorption lubrication layer 10, 20 Magneto-optical recording medium 100 Solid immersion lens

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 11/105 531 G11B 11/105 531M 531D 546 546F 546G // C10M 107/38 C10M 107/38 C10N 40: 18 F term (reference) 4H104 CD04A PA16 4J005 AA02 BD02 5D029 LA05 LA12 LB04 LB12 LB17 LC14 5D075 AA03 CD17 CF03 EE03 FG04 FG10 GG04 5D121 AA04 EE21 EE28 GG02 GG07 GG18

Claims (38)

[Claims] 1. An optical recording medium comprising a substrate and a lubricating layer composed of a reflective layer, a recording layer, a protective layer, and a lubricant in this order, wherein the lubricant has a lubricant binding rate of 60% with respect to the protective layer. ~ 1
An optical recording medium characterized in that it is 00%. 2. The perfluoropolypolymer having a molecular weight of 2,000 to 10,000, wherein the lubricant has one kind of functional group selected from the group consisting of an alcohol group, a carboxyl group, an ester group and a piperonyl group at one or both ends of the molecule. 2. The optical recording medium according to claim 1, wherein the medium is ether. 3. The optical recording medium according to claim 1, wherein said protective layer is made of carbon. 4. The optical recording medium according to claim 3, wherein said carbon contains at least one element selected from the group consisting of hydrogen, nitrogen, silicon and fluorine. 5. The method according to claim 1, wherein the lubricant bonding ratio is 80% to 100%.
The optical recording medium according to claim 4, wherein: 6. The optical recording medium according to claim 1, wherein said optical recording medium is a magneto-optical recording medium. 7. The optical recording medium according to claim 1, wherein at least one of recording and reproduction is performed by irradiating light from a lubricating layer side to the optical recording medium by a floating optical head. 8. The optical recording medium according to claim 7, wherein the flying optical head includes a solid immersion lens. 9. The optical recording medium according to claim 8, wherein the flying optical head further comprises a magnetic coil for applying a magnetic field to the optical recording medium. 10. The optical recording medium according to claim 1, wherein the lubricant is perfluoropolyether, and at least one molecular terminal group of the perfluoropolyether has two or more hydroxyl groups. . 11. The lubricant has a molecular weight of 2,000 to 10,
11. The optical recording medium according to claim 10, wherein the number is 000. 12. The method according to claim 12, wherein the lubricant is HO—CH ₂ CH (O
_{H) CH 2 OCH 2 CF 2} O- (C 2 F 4 O) n - (C
_{F 2 O) m -CF 2 CH} 2 OCH 2 CH (OH) CH 2
The optical recording medium according to claim 11, which is a perfluoropolyether represented by OH. 13. An optical recording medium comprising a substrate and a lubricating layer composed of a reflective layer, a recording layer, a protective layer, and a lubricating agent in this order, wherein the lubricating agent is perfluoropolyether; An optical recording medium, wherein at least one molecular terminal group of the polyether has two or more hydroxyl groups. 14. A lubricant having a molecular weight of 2,000 to 10,
14. The optical recording medium according to claim 13, wherein the number is 000. 15. The method according to claim 15, wherein the lubricant is HO—CH ₂ CH (O
_{H) CH 2 OCH 2 CF 2} O- (C 2 F 4 O) n - (C
_{F 2 O) m -CF 2 CH} 2 OCH 2 CH (OH) CH 2
The optical recording medium according to claim 14, wherein the optical recording medium is a perfluoropolyether represented by OH. 16. The optical recording medium according to claim 13, wherein a lubricant bonding ratio of the lubricant to the protective layer is 60% to 100%. 17. The optical recording medium according to claim 16, wherein said protective layer is made of carbon. 18. The method according to claim 18, wherein the carbon protective layer comprises hydrogen, nitrogen,
At least one selected from the group consisting of silicon and fluorine
18. The optical recording medium according to claim 17, containing a seed element. 19. The optical recording medium according to claim 13, wherein at least one of recording and reproduction is performed by irradiating light from a lubricating layer side to the optical recording medium by a floating optical head. 20. The optical recording medium according to claim 19, wherein said floating optical head includes a solid immersion lens. 21. The optical recording medium according to claim 20, wherein the flying optical head further comprises a magnetic coil for applying a magnetic field to the optical recording medium. 22. The optical recording medium according to claim 21, wherein the bonding ratio of the lubricant to the protective layer is 60% to 80%. 23. The optical recording medium according to claim 13, wherein said optical recording medium is a magneto-optical recording medium. 24. A method for manufacturing an optical recording medium comprising a reflective layer, a recording layer, a protective layer, and a lubricating layer on a substrate in this order. 60% to 100% of lubricant
%, Wherein a lubricating layer is formed by performing at least one of heating and ultraviolet irradiation so as to obtain a lubricating layer. 25. The optical recording medium according to claim 23, wherein the lubricant is perfluoropolyether, and at least one molecular terminal group of the perfluoropolyether has two or more hydroxyl groups. Manufacturing method. 26. The lubricant having a molecular weight of 2,000 to 10,
The method of manufacturing an optical recording medium according to claim 25, wherein the number is 000. 27. The method according to claim 27, wherein the lubricant is HO—CH ₂ CH (O
_{H) CH 2 OCH 2 CF 2} O- (C 2 F 4 O) n - (C
_{F 2 O) m -CF 2 CH} 2 OCH 2 CH (OH) CH 2
The method for producing an optical recording medium according to claim 26, wherein the method is perfluoropolyether represented by OH. 28. The temperature for heating is 50 ° C. to 12 ° C.
The method for manufacturing an optical recording medium according to claim 25, wherein the temperature is within a range of 0 ° C. 29. The method for manufacturing an optical recording medium according to claim 25, wherein the ultraviolet ray used for the ultraviolet ray irradiation is an ultraviolet ray having a wavelength of 185 nm to 254 nm. 30. The method for manufacturing an optical recording medium according to claim 24, further comprising washing the lubricating layer with a solvent after performing at least one of heating and ultraviolet irradiation. 31. The solvent, wherein the solvent is perfluorooctane,
Perfluorohexane, C ₄ F ₉ OCH ₃ , C ₄ F ₉ O
The method of manufacturing an optical recording medium according to claim 30, characterized in that the C ₂ H ₅ and one solvent selected from the group consisting of Galden. 32. The method according to claim 29, wherein the ultraviolet irradiation is performed in an inert atmosphere. 33. The method according to claim 32, wherein the inert atmosphere is an atmosphere selected from the group consisting of a nitrogen atmosphere, an argon atmosphere, and a helium atmosphere. 34. The method according to claim 24, wherein the optical recording medium is a magneto-optical recording medium. 35. The optical recording medium according to claim 24, wherein at least one of recording and reproduction is performed by irradiating light from the lubricating layer side by the floating optical head. Production method. 36. The method according to claim 35, wherein the flying optical head includes a solid immersion lens. 37. The method for manufacturing an optical recording medium according to claim 36, wherein the flying optical head further comprises a magnetic coil for applying a magnetic field to the optical recording medium. 38. An optical recording medium manufactured by the manufacturing method according to claim 23.